Aiwa NSX-VC78, Service Manual

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1. Tape Speed Adjustment (DECK 2)

Settings : • Test tape :

TTA-100 (3kHz)

• Test point :

TP10 (Lch), TP11 (Rch)

• Adjustment location : SFR1

Method : Play back the test tape and adjust SFR1 so that

the frequency counter reads 3000Hz 

±

 5Hz (FWD) and

±

 45Hz (REV) with respect to forward speed.

2. Head Azimuth Adjustment (DECK 1, DECK 2)

Settings : • Test tape :

TTA-300 (315/10kHz)

• Test point :

TP10 (Lch), TP11 (Rch)

• Adjustment location : Head azimuth

adjustment screw

Method : Play back the 10kHz signal of the test tape

and  adjust screw so that the output becomes
maximum. Next, perform on each FWD PLAY
and REV PLAY mode.

3. PB Frequency Response Check (DECK 1, DECK 2)

Settings : • Test tape :

TTA-300 (315/10kHz)

• Test point :

TP10 (Lch), TP11 (Rch)

Method : Play back the 315Hz and 10kHz signals of the

test tape and check that the output ratio of the
10kHz signal with respect to that of the 315Hz
signal is within 0 

±

 3dB.

4. PB  Sensitivity Check (DECK1, DECK2)

Settings : • Test tape :

TTA-200

• Test point :

TP10 (Lch), TP11 (Rch)

Method : Play back the test tape and check that the output level of

the test piont is 250mV 

±

 3dB.

5. REC/PB Frequency Response Adjustment (DECK 2)

Settings : • Test tape :

TTA-602 (Normal)

• Test point :

TP10 (Lch), TP11 (Rch)

• Input signal : 1kHz/10kHz (LINE IN)
• Adjustment location : SFR351 (Lch)

SFR352 (Rch)

Method : Apply a 1kHz signal and REC mode. Then adjust OSC

attenuator so that the output level at the test points
becomes 9.0mV. Record and play back the 1kHz and
10kHz signals and adjust SFRs so that the output level
of the 10kHz signals becomes 0dB 

±

 1.0dB with respect

to that of the 1kHz signal.

6. REC/PB Frequency Response Check (DECK 2)

Settings : • Test tape :

TTA-615 (CrO

2

)

• Test point :

TP10 (Lch), TP11 (Rch)

• Input signal : 1kHz/10kHz (LINE IN)

Method : Apply a 1kHz signal and REC mode. Then

Adjust OSC attenuator so that the output level
at the test points becomes 9.0mV. Record and
play back the 1kHz and 10kHz signals and
check that the output is 0dB 

±

 2dB.

7. REC/PB Sensitivity Check (DECK 2)

Settings : • Test tape :

TTA-615 (CrO

2

),

TTA-602 (Normal)

• Test point :

TP10 (Lch), TP11 (Rch)

• Input signal : 1kHz (LINE IN)

Method : Apply a 1kHz signal and REC mode. Then adjust OSC

attenuator so that the output level at the test points
becomes 90mV. Record and play back the 1kHz signal
and check that the output is -1dB 

±

 3dB.

<FRONT SECTION>

8.

µ

-CON OSC Adjustment

Settings : • Test point :

TP5 (K-SCAN) and TP6 (GND)

• Adjustment location : L101

Method : Insert AC plug with pressing of POWER and TUNER

function key. Adjust L101 so that the frequency across
the test point is 208.8Hz 

±

 0.2Hz.

< DECK  SECTION >